Copying and enlarging camera.



J. BECKER.

(.QPYING AM) ENLAHGING CAMERA.

AZPLIL'AIION HLED MN. 24. 1917. I

Patented Oct. 8, 191b,

5SHEEI'S SHEEI 1.

Jig a1 J. BECKER.

COPYING AND ENLARGING CAMERA.

APPLICATION FILED JAN. 24. 1917.

1,280,638. I Patented Oct. 8, 1918 5 SHEETSSHEET- 3- 1 T 1A I I I I I lg I I I i I I I I I I I I I i I l I I I I II i I y I I l I I L- 1....1 IL- L- I G e r b .J

G I?- rgai I G K,

5A L g o \o 2.0 0 0 5o 60 7o 8oo loo Inventor kw. M

J. BECKER.

COPYING AND ENLARGING CAMERA.

APPLICATION FILED JAN. 24. 1911.

1 280,638. Patented Oct. 8, 1918. SHEETS-SHEET 5.

7 FN=N'F"= f 24 cm FF'=(2f+NN')= 54 cm P o A oc= l-oooQ E; =A= Z=!-oooQm X I5 cm. m -x'= I9 cm.

AV .Dz I2 Cm,

Co-varyiny Newtonian Spaces PF AD =VZ 28-8 cm 1''? D'A' Z'V 20 cmInventor belng UNITED STATES PATENT OFFICE.

JOSEPH BECKER, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO EASTMANKODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

COPYING AND ENLARGING CAMERA.

' Specification of Letters Patent.

Patented Oct. 8, 1918.

Continuation of application Serial No. 732,488, filed November 20, 1912.This application filed January 24,

Y 1917. Serial 110. 144,264.

To all whom itmay concern:

Be it known that I, Josnrn B wKER, a citizen of the United States,residing at Cameras, of whichthe following is' a specification.

The present patent application, identified is a continuation of myherein merged and therefore expressly abandoned prior'a lication Case Y,Serial No. 732,488, filed W.- 20, 1912.

My present Case Au, and my other hereinafter specifically referred torelated applications or patents, may all be listed in their letter nameor filing date order, as follows: Case A, Serial No. 26,647, filedAugust 11, 1900, now Patent 1,178,474, issued pril 4, 1916; Case K, nowPatent 1,103,342, issued July 14, 1914; Case 0, now Patent 1,103,343,issued July 14, 1914; Case T, now Patent 1,142,295, issued June 8, 1915;Case U, now Patent 1,190,214, issued July 4, 1916; Case X, Serial No.727,548, filed December 24,

Case Y, (based on 1912, but now merged in and continued as the presentCase Au; British Patent 29,701, filed December 24, 1912; Case Ab, nowPatent1,178,477, issued A ril 4, 1916; Case Ae, Serial No. 66,371, fileDecember 11, 1915;

,lase Ai or Division 2 of A, Serial No. 88,619, filed April 3, 1916, butnow merged in and continuedas Case Bo; Case At, Serial No. 143,085,filed January 18, 1917 the present Case Au or continuation of Y, Ser1alNo. 144,264, filed January 24, 1917 and the still lat-er Case Be orcontinuation of Ai, Serial .No. 255,491, filed September 24, 1918.

in an improved specific form of t e radial cam mechanism that is usedfor automatically focusing the copying or enlarging cameras of my saidCase U, such improvement dependent upon the use of three specialstructural features, to wit: (1) special structural end frame terminalsA and A that are alined with the sector or lens frame pivot D, as in mysaid Cases K, O and T, and that for convenience of reference as my CaseAu,

' resent Fi s. 1 to 7), Serial No. 732,488, fi ed ,Novem er 20,-

'endframe pintles being now identified, in

my said Cases Ae, At, present Au, and later Bo, as pintles V'and V; (2)means for oilsetting the paths of the said two end frame pintles, V andV to any desired extent; (3) a focusing sector whose angle VDV' issmaller than a right an le.

' In the more general demonstrative form, present Fig. 4, I providestructural means for setting the sector angle VDB, also the twodependent or equal end frame angles, DAV and D'A'V, at any preferredvalue, either smaller, as shown, equalto, or larger than a right angle,so that my invention, in its broader aspects, does relate generally andwithout exception to all those varieties of .the theoretically exactradial cam focuser,

which have so far been disclosed by me, first in Figs. 1 to 24 in mysaid Case A, and then in nine of my said other cases, to wit: Cases U,X, Y, British, Ae, Ai,"At, present Au, and later Bo.

These ten different specifications treat of five different varieties ofthe radial cam focuser, to wit: 1) the wholly mechanical as in my saidCase U, and in the present Figs. 1 and 3; (2) the one-sight optical, ofmy said Case At; (3) the two-sight optical most clearly represented inFig. 3 of my said Case A; (4) the"double-sight optical most clearlyrepresented in Fig. 4 of my said Case A; (5) the theoretically importantdoubleender optical derived from Fig. 34 in my appears conclusively thatone same general rule of construction, adjustment, and regulation, mustgenerally be applicable to these five different varieties of the radialcam focuser.

While my present invention, therefore, re-

lates primarily to mechanical radial cam focusers having a basic anglethat is acute; in its more general aspects, it covers all thosevarieties ofthe either right or oblique angle theoretically exact radialcam focuser so far treated of by me as follows: (1) in Figs. 1

to 24 of my said Case A, as obtuse angle l optical focusers; (2) in mysaid Case U, as-

right angle mechanical focusers; (B) in my said Case X, as a specialform of the right angle mechanical focuser; (4) in my said Case Y, whichis based on present Figs. 1 to 7, as either right or oblique butpreferably acute angle mechanical focusers; (5) in my said Britishpatent, as right angle mechanical focusers; (6) in my said Case Ae, aseither right or oblique angle focusers, either optical. or mechanical,but mainly obtuse angle optical; (7) in my said Case Ai as obtuse angledouble-sight optical; (8) in my said case At as obtuse anglesingle-sight optical; (9) in the present Case Au, as either right oroblique but preferably acute angle mechanical focusers, with mechanicalfocuser forms that are sufficiently general to include as special cases,all other forms, either right or oblique angle, and either optical ormechanical; (10) in my said Case Be, as either right or oblique anglefocusers, either optical or mechanical, but mainly obtuse angle optical.

The optico-mechcmical foouser.

The mechanical focuser of Fig. 20 in my said Case U, with its terminal Alocated in its corresponding image plane P, may be called anoptico-mechanical focuser, because it is directly convertible into anoptical focuser, of the type disclosed in Figs. 1 to 24 of my said CaseA, by providing the lens frame of the camera, in the said Fig. 20, withany suitable means for sighting horizontally through D toward A, andthen obliquely from C, along CA. Point A, situated in the conjugateimage plane P, then virtually becomes a free external object point to bephotographed, geometrically identical with the object point 0 in Fig. 3of my said Case A, assuming angle OGA in said Fig. 3 to be a rightangle.

Any thus derived optical focuser, how-' ever, must have its pivot Cmounted directly over the external principal focus F of the camera lens,so that the angle NFC shall be a right angle, and this requires anoutrigger or bracket, like the imaginary bracket 02 DDC, that projectsout in front making the camera too cumbersome for use as a hand camera.

The device is rendered practical, however, by rotating the vector DC(which, considered pm" s e, may be made as long as desired)counter-clockwise, about D as geometrical pivot, so as to throw thestructural or sector pivot C of said Fig. 20 back where it will besituated directly over, or on, some part of the ordinary lens supportingframe of the camera.

In order that this change shall produce no change in the theoreticalaccuracy of the focuser, however, the pivoted sector angle ACA, and thestationary lens frame angle CDA must both be opened up to the sameextent. The two equal obtuse stationary lens frame angles ADC and CDA ofsaid Fig. 20 Case U are then made identical with the two equal obtusestationary lens frame angles 1' at G, and r at H, in Figs. 17, 18 and 23of my said Case A.

That is to say, the optical focusers of my said Case A are in factradial cam focusers whose basic angle, r at G, also '1" at H, is largerthan the right angle; whereas all radial cam focusers either shown oronly referred to in my said Case U, have the correspondin basic angle,at D and D, equal to t e qua rant or one right angle.

The mechanical focuser seen in Fig. 19 of my said Case U is convertedinto the o ticomechanical form by shifting the who e fo cusing gear, tothe right, through a distance equal to the length of the bar m so as tobring the terminal A into the image plane P. This makes m equal zero, asin Fig. 20.

In the complete form of focuser Fig. 12 of said Case U, it is sufficientto shift the riglit hand part CDA of the focusin gear to the'rightthrough the distance m The terminal pintleA of my said Case U reallycorresponds, not to the present terminal-A', but to the present terminalV; and, therefore, in the present Fig. 8, the bar that corresponds tobar m of my said Case U, is not bar m, but bar 112/.

This ends my rather long, but really necessary introductory explanationof the very close relationship that connects the optical type of radialcam focuser, seen in Figs. 1 to 24 of my said Case A, with the whollymechanical forms of the present Case Au.

Description of present F 2' 8. 1 to 13.

From the disclosuresmade in my said Cases A, and Ae, it appears that theobtuse angle radial cam is specially advantageous in optical focusers,whereas the acute angle radial cam is specially advantageous inmechanical focusers; and, therefore, while, as before stated, mybroadest present claim does include focusers of the obtuse-angle? type,my most specific present claim is limited to focusers of the acute-angletype.

As in my said prior Cases K, (),T, and U. all forms shown containlongitudinally adjustable connections between the gear proper and thecamera frames for at least two of the three camera frames, and the thirdcamera frame connection is preferably made longitudinally invariable,regardless of the properties of the lens to be used in the camera. As inmy prior application Case U, and in my said other applications, Cases K,O, and T, the drawings, for clearness, are limited to forms in whichthis third longitudinally invariable frame connection is that made withthe lens frame.

In the accompanying drawings where similar reference signs refer tosimilar parts:

Figure 1 is a longitudinal vertical section of. a copying or enlargingcamera having radial cam gear of the rectangular type with adjustmentsto ermit of settin the horizontal paths of t e end frame pintles at anydesired relative hei ht.

Fi 2 is a detail view 0 a modified form of a justable gear and frameconnection.

Fig. 3 is a longitudinal vertical section of 0. copying or enlargingcamera in every respect similar to the'camera of Fig. 1, but with radialcam gear of the acute an le type.

Fig. 4 shows a omplete form whic virtually embodies in one structure allother forms of radial cam focusin gear.

Fig. 5 is a diagram of ang es determined in Fig. 4.

Fig. 6 is a modified form of Fig. 3.

Fig. 7 illustrates my general three-point method of adjustment.

Figs. 8 to 13, with equations annexed as part thereof, are explanatorydiagrams.

112 is formed a longitudinal slideway 105 for a slide block 106,which'directly supports the object frame 0 and which has a set screw 107for clamping the object frame 0 in any desired longitudinal ad ustmenton carriage 112. The image frame I is s milarly clamped in any desiredlongitudinal adjustment on carria' 112' b means ofset screw 107 threadedin the slide block 106 of slideway 105'; and the lens frame L is rigidlyfixed 'to bed 110 by screws 103.

To the under side of carriage 112 is fastened by bolts 113 a bracket 114having a vertical slot 115' in which the object frame pintle V may beslid vertically to be clamped b a nut at any desired height on thebracket. T b the under side of carriage 112' is similarly fastened bybolts 113' a bracket 114 having a vertical slot 115 for the verticaladjustment of the image frame pintle V A transverse pin or rod D slippedhorizontally throu the bed 110 serves as a fulcrum for a ocusing lever116, 116', with rectangularly disposed radial cam slots The upper end ofslot 115 at the same level as pin D is enlarged to form a bore A ofthesame diameter as pin D, in order that the carriage 112 may be slidinto position to admit and be held temporarily by pin D while the objectframe 0 is being focused on righthand infinity. The upper end of slot115 is similarly provided with an opening A to permit of holdingcarriage 112 while the image frame I is being focused on left infinity.

riages (112, 112) by focusing on infinity, as

in my said cases K, O, T, and U they are set and temporarily held infocus on each other at a finite distance, say with their carriages inthe relative position shown in Fig. 1, where the copyin factor is madeexactly equal to 4/3, for c earness only, as no attention is paid to itsexact value. The lever 116 is thenmounted on its pin D and one of theend frame pintles, sa" V, is inserted and clamped at an desire elevationin the vertical slot 115. The other end frame pintle, here V, will thenhave to be inserted where itsvertical slot 115 is met by the radial slot117 and the device is ready for use. As pintles V, V when set as shownmove in offset horizontal planes, the device as adjusted in Fig. 1 isthe equivalent of the Stevens or Cook gear typified in Fig. 9 of my saidCase U, and which I refer to by these names because it first appeared inFrench Patent No. 330,565 of 1903 to Stevens, and then in British PatentNo. 12734 of 1901 to Cook.

'If the carriages 112, 112, be temporarily clamped in any finite focalrelation, that of Fig. 1, for instance, and pintles V, V both beloosened, any other desired operative value may be given to thedistances AV, A'V' by simply turning the sector 116, 116 on its pivot D.Thus by turning it clockwise AV may be reduced and AV increased until AVequals. AV'; and the device will then act as a Carpentier gear, the gearshown in Fig. 7 of my said Case U, and originally described in GermanPatent No. 102,004 of 1897 to Carpentier. By continuing the clockwiserotation, AV' may be made longer than AV and the device again becomes aStevens 0r Cook gear.

The camera of Fig. 1, therefore, permits of'realizing, not only allvarieties of focusing gear represented in Figs. 2, 7, 9, 10 and 18 to 20of my said Case U; but also all proportions of such different varieties.This is of practical importance because it allows the user to selectfreely the arrangement and the proportions of such arrangement thathappen to be the most satisfactory.

Block 106 and carriage 112 of Fig. 1 simply constitute a longitudinallyadjustable connection between the object plane P and the connectingpoint A to regulate the dimension m. This is more easily seen in Fig.

-by a telescoping rod 128. This rod 128 is fixed to the carriage 127 bypin 129, and it is clamped in any desired relation to block 126 by thescrew 130. The bracket 114 of Fig. 1 here becomes a plain arm 131.

The image frame would in this case preferably be mounted in the samemanner to regulate m by means of parts corresponding to said parts 126to .131 that need not be illustrated.

Non-rectangular type, Fig. 3 and F 6.

All radial cam focusing gear heretofore proposed is dependent upon themore or less evident presence of two co-varying but always similar basictriangles such as AD" and AVD, Fig. 1, that are rectangular at A and A.In Fig. 3, I show a form in all essential particulars similar to Fig. 1,but in which these same basic triangles are nonrectangular, with theconstant angle at A and A equal to seventy per cent. of a right angle(0.700 Q). In this Fig. 3 the camera bed 110, slideway 111, pin D,frames 0, L, I, the lens, the carriages 112, 112, and other parts 105,105', 106,106',107,107', 113,113 are all identical with the similarlyidentified parts of Fig. 1, so that the two figures differ only in thefocusing lever 216, 216 and in the brackets 214, 214. The bracket 214has an inclined slot 215 for the inclined adjustment of pintle V; andthe bracket 214' has an oppositely inclined slot 215' for the inclinedadjustment of pintle V. The upper ends of these slots 215, 215 at thelevel of pin D are enlarged to form holes A, A of the same diameter aspin D to permit of reducing the co-varying mechanical space elements DA,DA to zero value as in Fig. 1. The different inclinations are determinedby the rule that angles DAV and DAV shall each be equal to the angle VDVof the sector 216, 216' and the adjustments are made exactly as inFig. 1. Fig. 1, in fact, is simply the special case of Fig. 3 in whichthe angles, just referred to, are all three made equal to one rightangle. An obtuse angular form may be formed by making the same threeangles severally equal to an angle that is greater than a right angle.

The angle VDV of the focusing sector in Fig. 3 may, therefore, have anydesired value, that shown being per cent. of a right angle (0.700 Q).Within certain limits, the smaller this angle is made, the smoother themechanism will operate, especially if the driven pintle be set as low aspossible, and, therefore, the device may be constructed with the drivenpintle non-adjustable and permanently fixed in its lowest desirableoosition, as in Fig. 6.

The combination partly shown in Fig. 6 is made by simply unmountingbracket 214 in the combination of Fig. 3, and substituting the bracket314, so that all parts except this one bracket are the same in the twofigures. Bracket 314, Fig. 6, is deeply recessed at its right band edgein the region surrounding polnt A of Fig. 3, so that the object carriage112 may be slid up into zero position without removing the lens pivot D.

Fig. 6 shows carriage 112 in its zero'posi tion, that is, with theNewtonian space element AD of the focusing gear reduced to zero value,so that the other Newtonian space element DA of the gear must beinfinite. To reduce AD to zero value. therefore, the sect0r218 is simplyturned up into the sition where its image arm 216' is paralle to theslideway 111, this being the position that it would occupy if it wereinfinitely long and still in engagement with pin V carried to infinitywith its frame I.

By focusing the object frame 0 on right infinity as shown in the figure,it is, therefore, virtually focused on the image frame, and theco-warying Newtonian s ace elements PF, FP' of the lens are ma e exactlyequal to the corresponding co-va ing Newtornan space elements AD, DA 0the mech-' amsm.

In the combination of Fig. 6, therefore, the fundamental principles ofadjustment are exactly the same as in the combination of F i 3, the on]difference to be noted be ing t at point of Fig. 3 is real, while pointA of Fig. 6 is purely imaginary.

The position of point A with relation to bracket 314 is virtuallydetermined by the sector 218 and its position changes with the valuedelta (A) of the sector angle. The bracket 314 may, therefore, be usedwith a rectangular sector or with any other provided the image bracket214, 215 be made to form an angle DA'V equal to the sector angle delta(A) to be used.

When dimension m is determined by reducing the correslponding Newtonianspace elements DA, F to zero value the object frame 0 is virtuallycarried to left infinity. and the image is reduced-to a point F. On theother hand, when 0 is focused on right infinity, as in. Fig. 6, todetermine m the image s virtually made infinitely large; and when Pisfocused directly on P -the image is of any preferred finite size.

My infinity method of adjustment, therefore, from a purely mechanicalpoint of View, secures exact correspondence of the lens andgear forthree different values of the copying factor n, to wit: one infinitelysmall value, one infinitely large value and an intermediate or finitevalue. The adjustments secure what may be called a threepointcorrespondence between the mechanism and the lens; and this three-pointcorrespondence, in a theoretically accurate focuser such as the one hereconsidered, insures all-point correspondence.

Complete form, Fig. 4. Fig. 4 is a scale drawing of a completeadjustable form specially adapted to illustrate the general structuralconditions that apply to the cameras of Figs. 1 to 3. It is, how ever,sufiiciently general, as will appear presently in connection with thediagram Figs. 8 to 13, to explain the structural elements of everyconceivable form or type of radial cam focuser, either optical or whollymechanical.

Here 210 is a table or boardon which the lens frame L is firmly fastenedby screws 211. Slideways 212, 212 are fastened on the same table 210- byscrews 213, 213 in any arbitrarily selected position, but, in order toavoid the use of bevel gearing and other needless mechanicalcomplications, they .should preferably be set, as shown, exactlyparallel to the lens axis FF.

One of these two slideways is mounted directly on the table, while theother is held at a certain distance above in order that either shall befreely adjustable in its own plane parallel to the table 210, withoutfear of interfering with the other, to permit of setting the two in anydesired position. When set to overlap with their produced axes D, D incoincidence, the two points D, D merge into the one'point D of Figs. 1and 3.

Carriages 214, 21-1 are fitted in the slideways 212, 212 and serve tohold and support the movable object and image frames, which arediagrammatically represented by their focal planes P, P.

At point A of carriage 214, is pivoted an arm 215 with radial groove 216which is held at any inclination to the carriage by means of a sector217 with arcuate slot 218 and a clamp screw 219 that screws into thecarriage 214. The radial groove 21G provides adjustment for the objectframe pintle V, which has a nut or other suitable clamp. ing means topermit of clamping it in its slot 216 at any desired distance AV from A.Carriage 214 is similarly provided at A with the corresponding elements215 to 219' and with means to permit of clamping the image frame pintleV in its slot 216' at any desired distance VA from A.

At D on slideway 212 is mounted the bar 230 with radial cam slot 231 toadmit and cooperate with pintle V; and at D on slide way 212 is mountedthe radial cam 230' with radial slot 231 to admit and cooperate with theimage frame pintle V.

At D is also pivoted a second bar 232 which may be clamped in anydesired angular relation delta (A) to bar 230 by means of the overlappedarcs 233, 234 and clamp screw 235.

Arms 232 and 230' are connected by an adjustable link comprising linkelements 236 and 237 and a clamp screw 238. The length BB should beexactly equal to-DD' to form an articulated parallelogram Use of thecomplete form, Fig. 4.--The slideways 212, 212' are first locatedarbitrarily in any desired position, such as that illustrated, and barBB is set to make BB equal DD. Points D and D may henceforth beconceived as invariably connected with the principal focal planes F, Fof the lens at distances a w therefrom. and the setting of D and D maybe considered as a free adjustment of the distances m and 0a.

The distance of the object plane P from the object frame pintle, Ashould be m, equal as; and to surely permit of securing this equality,the connection on is made adjustable, as indicated by slides 240, 241and clamp bolt 242.

The distance m of the image plane P from the image frame pintle A issimilarly made adjustable by slides 240. 241. and clamp screw 242 topermit of making an exactly equal to m. It is evident that bars m and mmight both be invariable and that in such case the bars :0 and 00 shouldbe the adjustable bars, as explained in connection with Figs. 12 to 15of my said Case T. page 3. lines 80 to 89, where other variations arealso considered.

The two angles DAV. DAV". respec' tively designated by alpha (of) andalpha prime (1) in Fig. 5, should both be made equal to the sector angledelta (A), which may be a right angle, as in Fig. 1. or an obtuse angle,as in my Case Ae. and which is preferably made acute. as in Figs. 3 and4, when the focuser is mechanical.

The pintles V, V" are mounted at any desired d stances AV, VA from A andA that will form a product (AVVA) equal to the square of the focallength of the l ns.

Fig. 4 is drawn to scale, with angles alpha (or). delta (A) and alpha.prime (a), each canal to two-thirds of a right angle (0.667 The focallength f equal FN is 24 cm: and the internodal d stance NN. herepurposely made large,to show it is duly accounted for. is 6 cm. Thedistance m, equal :1, equals 11 cm. The dista ce m", equal m, equals 7cm. The product AVlVA or 25 23.(H equals 576 or F.

The four axes A, D. D. A are projected onto the lens axis F F byvertical planes and the alined point projections so obta ned aredesignated hythe four corresponding lower case letters a, d, d, a, sothat all structural conditions may conveniently be summed up in the fourfollowing equations, to wit:

therefore,

Pa, Fd, Pa, Fd shall be clearly separated. As a rule, in Figs. 1 and 3,for instance, they overlap and are not so easily distinguished. The fourcardinal points F, N, N, F of the lens and the two points (Z, (Z are allsix shown as black'dots to indicate that they are stationary; whereas,points P, a, a, P are shown as perforated or wheel dots to indicate thatthey move.

Equation 2 is satisfied by simply making m equal as, and equation 3 issimllarly satisfied by making m zv.

It is directly evident in Fig. 4 that in all cases I so that, ifequations 2 and 3 are satisfied, this equation becomes m+dd+m=FF (5)Moreover, when equation is satisfied, we

evidently have Pa Fd Pa aF aF Fd PF ad (6) Similarly, when equation 3 issatisfied, we have Pia! F/dl Pa+aF=aF+Fd PF=ad (7) In equations 6 and 7,PF and P'F' are the co-varying Newtonian space elements of the lens, andad, d'a are the corresponding and equally co-varying Newtonian spaceelements of the mechanism.

Referring now to the diagram, Fig. 5, where points D and D arestationary, and, shown as black dots, let VD and VD be produced to meetin C at an angle delta (A). Supposing equations 1 and 4 are satisfied,then AV and VA (shown in full lines), as well as angles alpha (0:) delta(A),

alpha prime (a) will henceforth remain invariable. All other sides showndotted AD, DV, AD, DV and the angles phi (o), omega (w) phi prime (cp)omega prime ((0') will vary during the operation of the device.

Drawing a line at C parallel to AD or D A to form the variable anglesphi second 9) and omega second (0)") respectively equal to phi (o) andomega prime ((0'), we have al+l +wl 2 If I and, noting that alpha (a),delta (A) and alpha prime (oz) were made equal by adjustment to satisfyequation 1, the last three equations yield II+ II I+ I whence bysubstituting for phi second alpha (or), phi omega (0) will remain,

res ect-ive y, equal to the angles alpha rime (a' ,phi prime (9), omegaprime (1-) and the triangles ADV, A'V'D will remain similar, ylelding AVD'A' ins-W This, in view of equations 4, 6 and 7, yields i v ad.d'a'=f"(8) Here ad and da are respectively equal to AD and DA', as beforestated, the covarying Newtonian space elements of the focusing gearcorresponding to the res ectively equal and similarly co-varyingewtonian space elements PF, F'P of the lens.

Equations 5 to 8 have all been derived from equations 1 to 4, in whichthey are im plied, so that in adjusting and regulating the devicenothing more need be done than to satisfy the first four e nations.

Equation 1 is readi y satisfied by direct adjustment of angles alpha(a), delta (A) and alpha prime equality of these three angles. In Fig. 5they are. each made equal to 0.667 Q, as before stated.

said prior Cases K, O, T and U, by simultaneously reducing the Newtonianspace element ad of the mechanism and the corresponding Newtonian spaceelement PF of the lens to zero value. This is done by hold ing axis Acoincident with axis D while focussing P on right infinity. Here m,equal to av, equals 11 cm.

Equation 3 is similarly satisfied by simultaneously reducing theNewtonian space element d'a of the mechanism and the correspondingNewtonian space element PF' of the lens to zero value; and this is doneby holding axis A in coincidence with axis D while focusing P on leftinfinity. Here m, equal to w, equals 7 cm.

Equation 4 is satisfied by selecting any desired position for pin V or Vand then determining the corresponding position for the other pin V or Vby focusing P directly on P. Here AV was selected as 25 cm; and VA,equal to 23.04, is sup osed to have been found by focusing P on at anypreferred finite distance.

Equation 2 is preferably satisfied, as in my.

(a) to secure the desired When the slideways 212, "212 of Fig. 4: areset in alinement withtheir produced axes D, D in coincidence, thedistances DD and BB are both reduced to' zero value and the completeform of Fig. 4 evolves into a simple form such as that of Figs. 1, 3 or6. In all simple forms, therefore, points D and D are merged in onepoint D which projects onto the lens axis as adouble point (1, cl, sothat equations 1 to 8 apply to the simple forms as well as they do tothe complete form by noting that in the simple forms dd is m'l.

General threespo int adjustment. My infinity method of adjustment andregulation, as explained above in connection with Fig. 6, virtuallyconsists in securing exact cooperation of the gear and lens for threedifferent focal relations of the camera frames; 1. e., for threedifferent values of the copying factor n, to Wit: one infinitely small,value; one infinitely large value; and, one in termediate or finitevalue.

These three different a values, however, may all three originally befinite, as will now be proved in connectionwith Fig. 7

In Fig. 7, let the movable end frames have their positions marked on thecamera bed 410 by drawing vertical lines, such G, G, in alinem'ent wlththe right hand faces of the frames as convenient planes of reference.

If now the object frame be set in, three different arbitrarily selectedpositions, O 0 indicated on the bedl ilO by marks G, H, K, the threeconjugate positions I, I I of the image frame I may be found by focusingwith a. ground glass, or by computa tion, or in any other preferredmanner; and

. then appropriately marked on the bed 410 as Any focusing mechanismthat is fully op erative should evidently oblige the image frame tosuccessively occupy the three different positions G, H, K, when theobject frame is made to successively occupy the positions G, H, K.

My focusing mechanism is provided with the three independent adjustmentsthat are necessary and sufficient to unconditionally and exactly securethis threefold correspondence, however irregular or arbiti. ,r'y thespacing of the marks G, H, K and G, H, K, may happen to be.

Let Y be the unknown position that frame 0 would come to if it were setin focus on right infinity; and similarly, let Y be the unknown positionthat frame I would come to if it were set in focus on left infinity.

Furthermore, let the known displacements GH,HK of the object frame be aand b, and

the unknown displacement HY be 1 The same letters primed, or for thecorresponding image frame.

Now, consider the a, b, y, may be used displacements of the frames inthe first posiand We are supposed to no ninr i tion 0 I. The distance YGor (y-l-c) must equal PF, the Newtonian space element of the lens; andthe distance YGr or (3 -a) must equal the coniugate Newtonian spaceelement F P We, therefore, have m W. I

The last two equations yield:

and, noting that 341 cancels f 30 cm 5:10 cm the len These four d. 5,llOWQ/ inserted in f yield. directly:

i c c If in equations 9 and 10 the quantities a and b be both madeinfinite we obtain:

yfzal and we see that the infinity method may be treated as a specialcase of this more general three-point method of adjustment.

This general threepoint method of adjustment with all three n valuesfinite is applicable in the manner just described to any one of thecameras shown in the present application and in my said. prior Cases K,O, T, U, Y, Ab, Ae, At, all of which are provided with means required.for reducing the Newtonian space elements of the focuser to zero value.

It is also applicable to my improved form of the Cook camera shown in myCase X, (Serial No. 727,548, filed October 2st, 1912) in the followingmanner: The four dimensions a, 0., b and 6 having been measured, compute-,/-iT b (n+6) (er/+5) elf-0'1;

Then set the object frame at distance f to the left of Y and the imageframe at distance f to the right of Y in order to place and temporarilyhold the two end frames in the unity position. Then make \VD equal DYE,equal 2f, to regulate the gear proper; and finally clamp the end framesto their carriages in the relative positions thus assumed. The mechanismwill then operate to make the end frames pass simultaneously through thecorresponding positions GG', HH, KK, and thisinsures an all-pointcorrespondence of lens and gear.

By means of this general three-point method, a lens specially designedfor a limited range of work can be accurately regulated for any threepair, or six, conjugate positions selected within the limits of itsrange of usefulness. The method is, therefore, specially valuable inregulating and adjusting to secure the sharpest chemical or actinicfocus.

Third method of adjustment.

When the focal length 7 of the lens is accurately known, the proportionsof the focusing mechanism proper can be constructed or adjusted inaccordance with such value and then the two dimensions m, m may bedetermined indirectly by means of the calculated Newtonian spaceelements AD, D'A corresponding to a determined value of the copyingfactor n which equals the ratio PQ/PQ of Figs. 1 and 3. For particulars,see the description of steps followed in adjusting and regulating theFig. 1 camera of my said prior Cases K and O.

In applying this third method to the improved Cook camera of my Case X,it is more convenient to calculate and use the full conjugate distancesPN, NP'.

Diagram, Fig. 8.

The diagram, Fig. 8, is similar in principle to Fig. 4, but analyticallmore complete, in that it shows two di erent sets of Newtonian spaces inthe mechanism, to wit: the old set AD, D'A, alread considered in Figs. 1to 6, and. a new set Z, ZV', whose elements will eventually enable us toshow the exact relations that exist between the various types of radialcam focusers shown or referred to in my different applications orpatents, as follows: First, in Figs. 1 to 24 of my Case A showingoptical focusers of the radial cam type with a basic angle r Fi 17 ofany pre erred value, but general y larger than a right angle; secondly,mechanical focusers of the radial cam type with a basic angle equal toone right angle shown or onlyreferred to in my said Case U aid in mysaid British Patent 29,701 of 1912;

thirdly, the radial cam focusing gear shown in my said Case X; fourthly,the radial cam focusing gear shown in Figs. 1 to 6 of m said Case Y,where the basic angle delta (Al may beof any desired value, to witrectangular, fixed oblique, 0r adjustable; fifthly, the either opticalor radial cam'focusing gear shown in my said Case Ae with a basic angledelta A) of any desired value; sixthlv. the radial cam optical focusinggear shown in my said Case At, filed January 18, 1917, where the sectorangle delta. A) is adjustable for use with any one of different lenses;seventhly, or generally, any one of the five different varieties of theradial cam focuser enumerated at the beginning of this specification.

The lens 509, as in- Fig. 4, is supposed to be stationary. 'Its fourcardinal points F, N, N, F are likewise stationary. and the fact thatthey do not move is indicated by showing them as black dots. The endframe conjugate points P and P, being on the contrary movable, are shownas perforated or wheel dots.

The same convention is adhered to in the mechanism where the four blackdots D, Z, D Z, indicate stationary lens frame points and the fourperforated or wheel dots A, V, A. V, indicate movable terminals thatmove with their respective end frames.

The left-hand radial cam 516, with radial cam slot '517, and pivoted onthe stationary lens frame terminal D causes the movable object frameterminal V, to move horizontally along path VZ in which Z is the zeroposition of V, or the position into which pintle V would come if theequal distances PF and AD were both reduced to zero value by setting theobject plane Pin focus on right hand infinity.

The right-hand radial cam 516, with we have throughoutall variations ofsuch.

Space.

PF=AD=VZ. (12) The spaces FP', D'A' and ZV are similarly, threerepresentations of the righthand varyin Newtonian space of thecombination, an we therefore have, throughout all variations of suchspace F'P=D'A=Z'V' (13) The co-varying mechanical space elements VZ, Z'Vtherefore constitute a second set of mechanical Newtonian spaces, whichmay be identified as the Z Z set, and which introduces anew set oflinear dimensions, to wit: DZ, DZ', m" a", m, w fyalso a new set ofangular dimensions, to wit: epsilon (e), the old delta (A) and epsilonprime (c'). These new dimensions are evidently connected in the same wayas the corresponding dimensions of the A A set, all as noted in thepaired equations collected in the table annexed to and formin part ofFig. 8.

From disclosures ma e in Figs. 12to 15 of my said Case T, page 3, line129, down to page 4, line 90, the accuracy of the relations notedrequires no additional proof.

By direct inspection in resent Fig. 8, it is furthermore seen that t etwo distances m and m" at the left are connected by the equationm"=m+AV. cos a (14) where the product AV. cos a is a constant to besubtracted from m, although the plus sign must be, used in theequation'beoause the cosine of alpha (0:), int ecase illustrated, is netive.

It is slmilarly evident t at the distances m' and m at the right areconnected by the equation I m"'=m'+A' V'. cos a (15) Now in order thatthe linear dimensions shall all be whole numbers, easily verifiable bscale and by computation, the basic angle a pha (a) used in Fig. 8 wasselected so that its cosine shall be exactly equal to minus one-third;and with an eight place table, this is found to be 109 28 16.4, ormoresim ply in quadrants 1.2163 Q which is approximately 1.2 or 6/5 of aright angle.

Abnormal type, Fig. 9.

66 If the clamp screw 535, in thef'normal combination Fig. 8, beloosened, and the radial cam 516 with the four terminals D, A, V, Z, allin their present relation, be rotated clockwise through an angle theta(6) We obtain the abnormal combination of Fig. 9, where the paths VZ, ZVproduced meet in X, at the same angle theta (6) and if now screw 535 beagain tightened, the two radial cams 516, 516 will operate as before tode termine the same co-varying constant product space elements VZ, ZV.

The new sector angle VDB, in Fig. 9, is really made up oftwo angles, toWit: the

7 basic angle delta (A) of the normal type,

Fi 8, plus the mutual inclination theta (6) at Fig. 9, of the paths VZ,ZV respectively described by the two pintles V and V. As a matter offact the sector angle VDB can in all cases, that is, in the normal type,Fig. 8 as well as in the abnormal type, Fig. 9, be represented by thegeneral equation VDB: (A+6) -Q. (16) for, in the normal type Fig. 8, thepaths VZ and ZV' are parallel, and their mutual inclination theta (6) is'm'l, so that we then have, in Fig. 8, VDB equal to delta plus zero,dorsimply equal to delta (A) as before state Straight lever type, Fig. 10.

l o'ffiny saidlcase A, as indicated in the present Fig. 10, by adding aneye and a line of s1 ht that passes longitudinally along the mid le lineof the lever.

Rz'ght imgle gear, Fig. 11.

Making the basic angle delta (A) in Fig. 8 equal to the quadrant, or oneright-angle, we obtain the complete diagram Fig. 11 of radial camfocusing gear having a basic angle equal to one right angle.

This Fig. 11, therefore, corresponds to Fig. 15 of my said Britishpatent, over which it has the advantage of clearly showing the exactrelation that exists between the rectangular focuser of my present Fig.1 to the rectangular focusers shown most clearly in Figs. 12 to.20 of mysaid Case U, where the co-variable similar triangles DAC and DCAcorrespond respectively to the present co-variable similar triangles ZVDand ZV'D'.

Fig. 12 type withcector angle VDB=180.

In 11 rotate the left combination VD clockwlse, about D, through oneright angle, and we produce the form shown in Fig. 12,

where the pintle V describes a path that is perpendicular to the path ofpintle V. Reduce DD and BB of Fig. 12 to zero value, and the two radialcams will form a straight lever of the first order, as in Marks, BritishPatent 13,934 of 1909, which is therefore seen to be radial cam gear ofthe rec tangular type.

Fig. 13 type with sector angle VBD=0.

In Fig. 11 rotate the left combination VD, counter-clockwise about D,through one right angle, instead of clockwise, and we produce the formshown in Fig. 13, where pintle V, as in Fig. 12, describes a path thatis also perpendicular to the path of the pintle V, but the direction ofthe path is reversed. Now make DD and its equal BB both equal to zero inFig. 13, and the two radial cams form a plain lever 0f the second orthird order, as in Fig. 3 of Cook, British Patent 12738 of 1904, whichis therefore also seen to be radial cam gear of the rectangular type.

General remarks.

. NOTE 1.In the simplest form, Fig. 6, the number of independentadjustments is 3, to wit: one (AV, Fig. 3) in the gear proper to satisfyequation 1, and two (m and m) in the frame connections to satisfyequations 2 and 3.

Nora 2.-As already explained in my said Case K (Notes 1 to 3 on pages 7and 8) any copying or enlarging camera, with automatic focusing gear ofany type whatever, requires the equivalent of these three independentadjustments, to wit: one in the varying velocity ratio gear, or focusingmechanism proper, to permit of making due allowance for all accidentaland contemplated variations in the focal length FN of the lens to beused; and two independent longitudinal adjustments in the frameconnections to permit of making due allowance for all accidental and allcontemplated variations in the extent, sign or location of theinternodal space NN of such lens.

Nora 3.Even when the camera is specially constructed for use with a lensof known make, standard type and size, some equivalent of these threeindependent adjustments is absolutely necessary, as fully explained inlines 41 to 85, page 9 of my said Case 0, to permit of surely securingin all cases the highest available efficiency of the particular lens tobe used. In current practice all lenses are different lenses; moreover,the use of the adjustments is so convenient and easy, that it willgenerally be resorted to as a time saver, even where all dimensionsinvolved are exactly known beforehand.

Nora 4.The four axial points a, d d, a are easily found in every simpleform and in every complete form of focusing gear direction andmagnitude,

illustrated in my prior cases K, O, T, U and X; and, therefore, theabove equations 2, 8, 5, 6, 7 and 8 apply generally and in everyinstance without exception or qualification.

No'rn 5.The co-varying mechanical space elements of any conceivable formof focusing mechanism necessaril corres mi in whole or in part to themechanical ewtonian space elements ad, da of equation 6; and, therefore,equations 2, 3, 5, 6, 7 and 8 may be applied to all possible forms ofautomatic focusing cameras, even to such as shown in U. S. patent toStender, No. 730,583, where the end frame pintles p p project onto thelens axis at a and a, and where the spiral cam grooves, by whatevercorrect rule they may have been lotted, must if sufliciently extendedtoward e lens,

necessarily contain zero points that project 3 onto the lens axis as dand d.

Nora 6.The presence of ity ratio mechanism to change the v velocityratio displacements of the focusing gear pro er (either in direction asin Marks,

r1tish atent 13934 of 1909; or, in both as in F1 3 and lines 20 to 24,page 8 of Cook, Britlsh Patent 12734 of 1904) does not alter thefundamental principles involved.

N ore 6.How a constant velocity ratio transmission, with suitableadjustments, may be utilized in combination with any conceivable type ofotherwise non-adjustable but theoretically accurate focusing mechanism,to permit of using such mechanism with any one of different lenses, isset forth in my said Case Ab.

No'rn 7.The lens frame has invariably been shown as the fixed frame, notbecause this is the preferred construction, but simply because it is theclearest; in this connection see Note 1 on page 4 of my said Case T.

No'rn 8.Any one of the four terminals A, D, D, A, of the two Newtonianspace elements ad, da' of the mechanism may be totally absent or purelyimaginary, as, for instance point A in Fig. 6. Four such 3- terminalconbinations are possible, to wit:

' Case 1, D D' A Case 2, A D A Case 3, A 'D A Case 4, A D D No'rn 9.Anytwo of the four terminals A, D, D, A may be absent or purely imaginaryif they do not belong to the same New- Nora 10.-When D and D are mergedin a constant veloc- Patent No.

. all four terminals Case 4, A D Case 6 D Case 7, A A

NOTE 11.Case 7 is a very common one. It presents itself, for instance,in Fig. 1, of Thompson British Patent No. 5583 of 1903, corresponding toFig. 1 of Stender, U. S

No'rr. 12.-Case 7 resents itself also in Fig. 10 of my said ase U bysuppressing the short crossbar 101 used to structural y represent theterminals D and D. When such bar 101 is absent, either carriage 100 or100 may be slid up into its zero position, without removing itsrespectiy'e-pintle A or A, by simply settin the radial cams of the otherpintle in para el relation, both pointing to infinity, exactly as theywould be held by such other pintle, A or A, carried to infinity.

Nora 13.-Case 7 presents itself in Fig. 2 of my said Case U bysuppressing the short cross-bar 14, so that the carriages 30, 30' mayfreely be moved u into zero position by the radial cam itse f.

\ Nora 14.-Any special provision to permit of conveniently reducingeither of the Newtonian space elements ad, da of the mechanism to zerovalue will answer, although some structural representation of A D, D, A,as in Fig. lgl'of my said Case is generally prefera e.

Nora 15.-In Fi 8 of Thompson, British Patent No. 5583 o 1903, pin .pprojects as A and pin 7) projects as D; the lens frame terminal D andthe image-frarne terminal A are imaginary, as in Case 8.

Norm 16.My said Case A already discloses, in Figs. 1 to 24 (and moreparticularly in Fig. 17) with text in lines 33 to 40 of page 9, (also inthe two equations annexed to and forming part of Fig. 23) a number ofdifferent t eoretically exact optical focusers which are of the radialcam t pc with a basic an le, 1* at G and r at H,

ig. 23, that may di er from a right angle by any desired amount, eitherin excess or in deficiency, and usually in excess; but for reasons givenin lines 12 'to 63, page 3 of said Case A, no claims whatever were made,

in said Case A, to such focusers of the radial cam type, and this factis more particularly noted in lines 54 to 57, page 3, of said Case A.

Nora 17 .-I am aware that the acute sector angle VDV of my Fig. 3, inthe special are set to case where the pintles V and V making, in saidCase A, any to a radial cam focuser;

move in the same horizontal plane, corresponds geometrically to theacute angle AUA' pivoted at U in Fig. 71 page 93, of Cremona, Elementsof Projectiee Geometry, Oxford, 1885; copyat Library of Congress. ThisCremona disclosure. however, is: first, purely geometrical ;,secondly,not sufficiently general, in such geometrical'treatment, for presentpurposes; thirdly, so involved with. other, and there more importantconsidera-- tions, that these completely obscure those properties of thecombination which are now proved of value in optics, by my present CaseAu.

Nora 18.-After the device of Fig. 4 has been fully adjusted for a givenlens, it is clear that it might be adjusted for a slightly differentlens and one given position of the object frame, by simply varying thesector angle delta (A) to shift the image frame as required. Suchadjustment, however, would be illegitimate and would generally introduceerror in all other positions of the end frame. A similar objectionapplies to the use of only two adjustments. Hence any change in the lenscalls for a repetition of three independent focusing adjustments, evenwhere any one or more of adjustments is found to be such as to requireno alteration for the new lens, be cause the fact that no change isrequired, in any one of the adjustable but normally rigid dimensions,can only be ascertained by a focusing operation. A legitimate adjustmentof the sector angle delta (A) is described in my said Case At.

Nora 19.-In the optical focuser of my said Case At (just referred to inNote 18 above) only two of the angular adjustments shown in my present,Fig. 4-. are used, to wit: the adjustment to vary the sector angle VDBor delta (A), and the adjustment to vary the end frame angle DAV thesetwo are sufiicient to permit of satisfying the present Equation 1.

No'rn 20.-Fig, 19 of my said Case A already shows a radial cam focuserwhose basic angle, equal to GG' N is non-rectangular and which has thesufficient number and kind of adjustments to permit of securing3-andall-point correspondence between the said focuser and any one ofdifferent lenses. Such adjustments, however, are not independent,because they involve a tentative or trial setting, and I accordinglyrefrained from claims whatever and such failure to claim is specificallynoted in the printed specification of said Case A, page 3, lines 5a to57, with reasons in'support thereof in lines 12 to 63 of the same page.

Nora 21.-My later Case 'Ae, filed in 1915 and my still later Case Atfiled in 1917 finally complete the proof which is now contained n myfive Cases A, U, Y, Ae and At such three that the principles ofconstruction and adjustment first disclosed in Fig. 4 of my sa1 d CaseY, are general and are directly applicable in designing radialca'm'focusers either optical or mechanical and either shown or onlyreferred to in my said five Cases A, U, Y, Ac, and At.

Non: 22.-I am aware that Professor Elie in the Journal de Physique,Paris, 1880, pages 162 to 164, diagrammatically proposes what must be aform of non-rectangular radial cam for directly connecting the two axialconjugate foci P and P of a lens with its principal foci F and F, andwith each other so as to determine the Newtonian spaces PF and FF of thelens directly; but the Elie disclosure is hardly more than a form oflens graphics, and is, moreover, of such nature as to exclude all theindependently variable linear elements of my various equations,.so thatit would not permit of constructing any one of the practical radial camfocusers shown in my said Cases A, U, Y or present Au, and Case At.

No'rn 23.A construction which must closely resemble what Professor Eliemay have had in mind is derived from my Fig. 8, as follows: In Fig. 8make the four bracket elements AV, A'V', DZ and D'Z each equal to I;make the two equal distances PV and F Z each equal to zero; finally makethe two equal distances PV and FZ each equal to zero; and observe:first, that every restric tion here made adds to the impracticability ofthe device as a focuser; secondly, that my Fig. 8, which is itselfhardly more than a diagram, never could be derived from the Elie sketch,although it does comprise, as just seen, all that may be implied in thesaid Elie project.

No'rn 24.My said Case A, page 20, Note 2, says that The specificinvention involved of Figs. 1 to 24 is completed and, therefore, claimedin my said Case Ae. The said Case Ae, however, still lacks completeness,as a general case, in that it does not contain adjustments for changingthe .value ofthe basic angle delta (A). Such angular adjustments arehowever disclosed by me, first, in Fig. 4 of my said earlier Case :Y;secondly, in Fig. 5 in my said, later Case At; and thirdly, in Figs. 4and 8 to 13 of my present Case Au continuing Y. Moreover, as the presentCase Au is the first to go to issue with a reasonably completedisclosure of all possible variations that may be made in the normallyrigid structural dimensions of a radial cam focuser. I am making mybroadest possible claim for an oblique angle radial cam focuser in thepresent Case Au, instead of making it in the said Case Ae, ascontemplated in 1916 before the present application Case Au had beenfiled No'rn 25.From disclosures made (1% In my said Case Ac; (2) in thepresent use Au Case Be, it is plain that any tvpe of radial cam opticalfocuser seen in Figs. 1 to 24 of my said Case A may be derived from mypresent Fig. 8 without making any change 1n the co-varying triangles ZVDand Z'D'V' by simply designing Fig. 8 so as to make the dimension on"equal to zero; for, this places the terminal V in the right hand con uate plane P considered as external object p ane to be photographed.

Nora 26.My said case At is the first to disclose the use of adjustmentsin the basic angle as a direct means use with any one of differentlenses.

What I claim as new and desire to secure by Letters Patent, is

he combination comprisin a photographic camera and a focuser of theradial cam type, said focuser having a basic an le, herein designated bydelta (A), which di ers from a right angle.

2. The combination comprising a photographic camera and a focuser of theradial cam type, said focuser having a basic angle, herein designated bydelta (A), which is smaller than a right angle.

3. The combination comprising a copying or enlarging camera hav' awholly mechanical focuser of the radi dl cam type, said focuser havinga. basic angle herein designated by delta (A) which diflers from 8 rightangle.

4. The combination com rising a photographic camera having a w ollymechanical focuser of the radial cam type, said focuser havinga basicangle, herein designated by deltla (A), which is smaller than a rightang e.

5. The combination with a photographic support and an image support, andmeans for guiding two of these three supports with relation to the thirdso that the relative positions of the said three supports may be changedas required to permit of securing any desired size the sharpest image ofbeing connected by a me-' camera com risin an ob ect an a lens in thetheoretically exact focuslng dGVICBS p 1 ppm-t said three supportschanical focuser of the radial cam basic angle, herein designated bydelta (A), is non-rectangular or oblique.

6. The combination with a photographic camera having a focuser of theradial cam type comprising: first, a radial arm adapted to connect thelens frame of the camera with its plate or film-holding frame; secondly,a second radial element mounted on the same said lens frame of thecamera and adapted to register with a specific point that is connectedwith the material conjugate focal plane; thirdly means connecting saidfirst two radial elements so they shall rotate in constant angularrelation, such connecting of regulation for,

type, whose ;(3) and especially, in my said later ions in Letters PatentNo. 1,280,638-

H O Q) sa. o

larging camera comprising a lens frame and two end frames, also guldesto permit of changing the relative positions of said three frames asrequired to secure a sharply focused image at any desired scale ofreproduction; of mechanism connecting said three frames to cause two ofthem to move with relation to the third so as to keep the said two endframes in focus on each other; said mechanism comprising two radial camsmechanically connected to turn simultaneously through equal angles; saidradial cams being pivoted ment with the said end frames respectively;

correction as follows:

on the said lens frame and}; having combined pivotal and slidingengage-= It is hereby certified that in Letters Patent No. 1,280,638,1918, upon the application of Joseph Becker, of Washington,

page 6, lines 89-90, strike out the phrase respectively equal to otaland sliding engagement, said pivot terminal being adwstable on itsrespective en frame in a direction that corresponds to the zero positionof its respective radial cam.

8. A copying or enlarging camera with automatic focusing gear of theradial cam ty e, such gear comprising two radial cam o l ments arrangedat an angle differing from a right angle, and connectionstocause thesaid two radial cam elements to turn simultaneously through equal andsimilarly directed angles.

9. A copying or enlarging camera with automatic focusing gear of theradial cam type, such gear comprising two radial cam elements arrangedat an acute an 1e, and connections to cause the said two ra' ial camelements to turn simultaneously through equal angles.

In testimony whereof, I have signed my name to this specification.

, JOSEPH BECKER.

granted October 8, District of Columbia,

for an improvement in Copying and Enlarging Cameras, errors appearrequiring In the drawings, Sheet 2, Fig. 4, under the referencenumeral230' for the reference-letter B read B; in the printed specification,

AD and D A;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this l th day of November, A. 11, 19 18.

[scan] v R. F. WHITEHEAD,

Acting Commissioner of Pat ents.

